Peavey VB2 bummer - out again!

[walknbluez]

edit: I tried to change the thread title because it looks like it is going to be fixed for good, but it won't change.

I love this amp and so it's like my kid getting sick. Anyway, plugged in tonight and it made a little crackle and went out, almost sounded like it was just the instrument cable. But it wasn't. All the tubes are lit. Just like the first time this happened when it was the internal fuse and was due to the bad batch of fuses in initial production. I had it repaired by a Peavey authorized dealer. So one would think that the fuse would no longer be an issue. There is an external fuse in the back as well but not sure if that is it because its frosted so you can't see the inside. Does anyone know if it could possibly just be this external fuse?

[XtraLongScale]

Nobody here on TB can give you the answer you want. I'm assuming the head's under warranty so you should just give Peavey a call and set up another repair at your local Peavey tech. I went through the blown fuse issue twice and on the 2nd go around, I gave the repair dept hell about needing this head to not die on me in the middle of a performance and some other rants about Peavey quality. They replaced the fuse and a couple other parts I can't recall. It's been almost a year since I've had it back and it's given me no problems since. They just had some crummy QC with a batch of those heads and you and I are the beneficiaries of that crummy QC. Again, since that last repair, my VB-2 is a total champ so take another swing and don't be afraid to bust some balls with the repair dept so they know you mean business. Been loving my VB-2 ever since. Good luck.

[mech]

10 to 1 the prob is an intermittent tube. Can be very difficult to track down.

mech

[BassmanPaul]

If the amp is under warranty I suggest you use it. Take the amp in and let a tech sort out the problem. If the HV fuse is blowing there is something wrong with the amp.

Paul

[carbonfold]

I had a simlar issue with one of my VB-2 heads. Blew the fuses out left and right (was not the FA2 1.5A fuse problem). Found out to be a bad transformer diode blowing out the F2 fuse.

Head was down in two separate shops and out of my hands for 1.5 months!! ergh!! But it was finally fixed.

[walknbluez]

Originally Posted by carbonfold

I had a simlar issue with one of my VB-2 heads. Blew the fuses out left and right (was not the FA2 1.5A fuse problem). Found out to be a bad transformer diode blowing out the F2 fuse.

Head was down in two separate shops and out of my hands for 1.5 months!! ergh!! But it was finally fixed.

What is the F2 fuse? Is that the internal or external?

[carbonfold]

The F2 fuse can be internal or external, depending on the brand of amplifier.

The VB2 F2 fuse is internal and will usually blow if you have a power tube failure. Beats me why they mounted and soldered it to a board (I would guess on cost cutting ) instead of doing like most tube amps and have it mounted in the back next to the main fuse.

"IF" and only if you have a shop work on it, they might wire you in fuse clips when they replace that fuse. Everytime a power tube fails (everytime I had one go out), this fuse will blow with it. If my memory serves me correct, it blows when there is a voltage spike to prevent further damage to the transformer (I believe).

[walknbluez]

Originally Posted by carbonfold

It is an internal fuse that usually blows if you have a power tube failure. Beats me why they mounted and soldered it to a board (I would guess on cost cutting ) instead of doing like most tube amps and have it mounted in the back next to the main fuse.

"IF" and only if you have a shop work on it, they might wire you in fuse clips when they replace that fuse. Everytime a power tube fails (everytime I had one go out), this fuse will blow with it. If my memory serves me correct, it blows when there is a voltage spike to prevent further damage to the transformer (I believe).

Ok but the tubes are all still lit up. If a power tube fails, does it still light up?

[carbonfold]

You can have power tube failure or blow that fuse and the tubes still appear to be lit.

[walknbluez]

Originally Posted by carbonfold

You can have power tube failure or blow that fuse and the tubes still appear to be lit.

Yeah I remember that now. Last time a whole new set of Ruby EL34BHT's were put in.

I have an extended warranty from GC. Let's see what kind of runaround I get this time. Last time was a huge clustermuck.

[BassmanPaul]

Originally Posted by carbonfold

Beats me why they mounted and soldered it to a board (I would guess on cost cutting ) instead of doing like most tube amps and have it mounted in the back next to the main fuse.

I very much doubt it was a cost cutting move. HV fuses can have a huge amount of voltage on them. Putting that voltage within reach of a user replacing the fuse with the amp powered up makes no sense.

Paul

[Jaco who?]

Originally Posted by walknbluez

There is an external fuse in the back as well but not sure if that is it because its frosted so you can't see the inside. Does anyone know if it could possibly just be this external fuse?

Might seem obvious, and maybe a little condescending, but everyone should have an ohmeter/multimeter for this sort of thing. Even a really cheap radio shack one. I've never trusted my eyes with fuses, even 30 years ago when they still worked.

[carbonfold]

Well, any heavy tube user needs some simple tricks and trades to bias their own amps unless you just have the cash laying around to pay someone to do it. Yes mA/A are dangerous beast, with the right training (in my book) anyone with common sense can safely change a tube and fuse out (most people know what lock out / tag out means ). But you still have people out there you want to keep away from this stuff, but I've been saying the same thing about drivers on the roadways for YEARS !!

But, mainly I said that because if you look on the back of almost all tube heads (usually) you can change that fuse out and the main fuse. But if the issue is having a fuse that you can remove with the amp on, then why would their still be a main fuse that you can expose on the back?

Fuses are there for a reason. But the F2 fuse is one that will go under normal tube failure circumstances "usually". However, I just don't see that this one amplifier holds itself at a higher standard to value safety with the F2 fuse being soldered to the board v.s. Ampeg, Orange or other Peavey amplifiers with the F2 fuse in the back.

I dunno, maybe I just see an industry standard to have that fuse in the back or on a replacable clip. Very annoying to have to solder it everytime.... my 2 cents anyways

Originally Posted by BassmanPaul

I very much doubt it was a cost cutting move. HV fuses can have a huge amount of voltage on them. Putting that voltage within reach of a user replacing the fuse with the amp powered up makes no sense.

Paul

[BassmanPaul]

There is a vast difference between a fuse carrying 120V AC or round 240V in other countries and 600+ volts on a high voltage fuse.

I am of the opinion that far too many musicians open up their amps hoping to fix them themselves. With no training they are risking their lives to save a few bucks. The results of this are often much larger repair bills. All of us who work as techs have seen the results of these attempts. If your Microwave oven failed would anyone open it up to see if they could fix it???? Only a fool would do so!

Paul

[mech]

FYI..the B+ fuse is mounted in fuse clips that are soldered into the pcb and the fuse is easy to change.

I fixed many amps that had external fuses wrapped in tinfoil or that were replaced with car fuses to "just make it through the gig". Those repairs usually required a new power transformer besides the parts for the real problem. I'm glad car fuses are now a different form factor and no longer compatible and that gum isn't wrapped in foil covered wax paper.

I like the fuses being inside the amp. Keeps the damage to a minimum and repair costs down.

edit: BassmanPaul..seems we were typing about the same time.

mech

[BassmanPaul]

Originally Posted by mech

I fixed many amps that had external fuses wrapped in tinfoil or that were replaced with car fuses to "just make it through the gig". Those repairs usually required a new power transformer besides the parts for the real problem.

The old cigarette foil round the fuse trick eh!!!

Wish I had a buck for every time I've seen that one!!! Last time I did see it the B+ fuse had been replaced with a nail. Took out all the iron in the amp. Such a waste!

Paul

[carbonfold]

true true.... if the perception is for the greater good of the people who should touch it in the first place.... But, again, it is hard to argue safety when most mfg companies put in a location that is........rather "easy" to replace (if ya know what I mean). But all this is IMO

BUT, with most things that is true no matter where you go. If someone is looking to get shocked, they will find a way... safety or not

[rbonner]

Originally Posted by BassmanPaul

Last time I did see it the B+ fuse had been replaced with a nail. Took out all the iron in the amp. Such a waste!

Paul

Yeah, fuses are for sissies.

[Bassmec]

Originally Posted by BassmanPaul

I very much doubt it was a cost cutting move. HV fuses can have a huge amount of voltage on them. Putting that voltage within reach of a user replacing the fuse with the amp powered up makes no sense.

Paul

I am all for introducing more danger wherever possible in this
mad heath and safety obsessed world.
Natural selection will sort it out Paul, don't you worry mate!, bass players should have aptitude tests, like:
1) Can you get an 8 X 10 non neo cab from a stage to a truck without the assistance of the emergency medical services?.
2) Can you change a tube and check the bias on your amp without requiring the services of an undertaker?.
ETC ETC
PS Introducing 240 volts as the new US household standard would go somewhere in the right direction of reducing voltage drops and inductive voltage spikes generally with the small added advantage of reducing the burgeoning population of the terminally incompetent to a small degree.
The dangerous thing in ht fuses is the shift to modern bayonet fitting 5 X 20mm fuse types away from the rather better designed 1 1/4" old school type fuses and fittings.

[Bassmec]

Originally Posted by rbonner

Yeah, fuses are for sissies.

In the good old days a .22 LR round fitted just fine and dandy!.
If you couldn't find a nail.